U.S. patent application number 13/899464 was filed with the patent office on 2013-11-28 for method of manufacturing organic light emitting display panel.
This patent application is currently assigned to LG Display Co., Ltd.. The applicant listed for this patent is LG Display Co., Ltd.. Invention is credited to In-Seok Kim, Sung-Ho Lee, Hyun-Taek Lim, Myung-Jae Yoo, Hui-Seong Yu.
Application Number | 20130316475 13/899464 |
Document ID | / |
Family ID | 49621906 |
Filed Date | 2013-11-28 |
United States Patent
Application |
20130316475 |
Kind Code |
A1 |
Yu; Hui-Seong ; et
al. |
November 28, 2013 |
METHOD OF MANUFACTURING ORGANIC LIGHT EMITTING DISPLAY PANEL
Abstract
A method of manufacturing an organic light emitting display
panel forming a protective insulating film in a luminescent region
without causing defects in a pattern is disclosed. The method of
manufacturing an organic light emitting display panel includes
forming a substrate having a luminescent region and a pad region,
simultaneously forming a light emitting cell in the luminescent
region and an organic pattern in the pad region, forming a
protective insulating film over the substrate, bonding the
substrate provided with the protective insulating film and the
sealing substrate using an adhesive film formed in a region
corresponding to the luminescent region, cutting the bonded
substrate provided with the protective insulating film and the
sealing substrate into a plurality of unit panels to expose the pad
region, and removing the protective insulating film and the organic
pattern in the exposed pad region.
Inventors: |
Yu; Hui-Seong; (Jeonju-si,
KR) ; Lee; Sung-Ho; (Daegu, KR) ; Lim;
Hyun-Taek; (Busan, KR) ; Kim; In-Seok;
(Gumi-si, KR) ; Yoo; Myung-Jae; (Busan,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG Display Co., Ltd. |
Seoul |
|
KR |
|
|
Assignee: |
LG Display Co., Ltd.
Seoul
KR
|
Family ID: |
49621906 |
Appl. No.: |
13/899464 |
Filed: |
May 21, 2013 |
Current U.S.
Class: |
438/26 |
Current CPC
Class: |
H01L 2251/566 20130101;
H01L 27/3276 20130101; H01L 51/56 20130101; H01L 51/5253 20130101;
H01L 51/524 20130101 |
Class at
Publication: |
438/26 |
International
Class: |
H01L 51/56 20060101
H01L051/56 |
Foreign Application Data
Date |
Code |
Application Number |
May 22, 2012 |
KR |
10-2012-0054091 |
Claims
1. A method of manufacturing an organic light emitting display
panel, the method comprising: forming a substrate having a
luminescent region and a pad region; simultaneously forming a light
emitting cell in the luminescent region and an organic pattern in
the pad region; forming a protective insulating film over the
substrate; bonding the substrate provided with the protective
insulating film and a sealing substrate using an adhesive film
formed in a region corresponding to the luminescent region; cutting
the bonded substrate provided with the protective insulating film
and the sealing substrate into a plurality of unit panels to expose
the pad region; and removing the protective insulating film and the
organic pattern in the exposed pad region.
2. The method according to claim 1, wherein the forming of the
light emitting cell and the organic pattern comprises
simultaneously forming the organic pattern and at least one of an
organic light emitting layer of the light emitting cell and a bank
insulating film defining the organic light emitting layer using the
same material, wherein the organic pattern is separated from the at
least one of the simultaneously formed organic light emitting layer
and bank insulating film.
3. The method according to claim 1, wherein the removing of the
protective insulating film and the organic pattern in the exposed
pad region comprises: adhering an adhesive tape to the substrate;
removing the protective insulating film disposed in the pad region
and adhered to the adhesive tape by peeling off the adhesive tape;
and removing the organic pattern of the pad region by immersing the
entire substrate from which the protective insulating film is
removed or the pad region in an etchant.
4. The method according to claim 3, wherein the removing of the
protective insulating film and the organic pattern in the exposed
pad region further comprises irradiating ultrasonic waves to the
pad region immersed in the etchant, the etchant comprising
isopropyl alcohol.
5. The method according to claim 1, wherein the removing of the
protective insulating film and the organic pattern in the exposed
pad region comprises: adhering an adhesive tape to the substrate;
removing the protective insulating film disposed in the pad region
and adhered to the adhesive tape by peeling off the adhesive tape;
immersing the entire substrate from which the protective insulating
film is removed or the pad region in deionized water; and removing
the organic pattern of the pad region by irradiating ultrasonic
waves to the pad region immersed in deionized water.
6. The method according to claim 1, wherein the removing of the
protective insulating film and the organic pattern in the exposed
pad region comprises: adhering an adhesive tape to the substrate;
removing the protective insulating film disposed in the pad region
and adhered to the adhesive tape by peeling off the adhesive tape;
removing the protective insulating film in the pad region to which
the adhesive tape is adhered by peeling-off the adhesive tape; and
evaporating the organic pattern by irradiating laser beams to the
organic pattern of the pad region exposed by removal of the
protective insulating film.
7. The method according to claim 6, wherein the evaporating of the
organic pattern by irradiating laser beams to the organic pattern
of the pad region comprises evaporating the organic pattern using
energy of the laser beams absorbed by pad electrodes having
octagonal or circular shapes and formed in the pad region to remove
the organic pattern.
8. The method according to claim 3, wherein the adhesive tape is
adhered to the substrate to protrude from at least one of a
plurality of sides of the substrate.
9. The method according to claim 5, wherein the adhesive tape is
adhered to the substrate to protrude from at least one of a
plurality of sides of the substrate.
10. The method according to claim 6, wherein the adhesive tape is
adhered to the substrate to protrude from at least one of a
plurality of sides of the substrate.
11. The method according to claim 1, wherein the removing of the
protective insulating film and the organic pattern in the exposed
pad region comprises: immersing the entire substrate or the pad
region in an etchant comprising isopropyl alcohol or deionized
water after the cutting process; and simultaneously removing the
organic pattern of the pad region by irradiating ultrasonic waves
to the pad region immersed in the etchant comprising isopropyl
alcohol or deionized water and the protective insulating film
formed on the organic pattern.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent
Application No. 10-2012-0054091, filed on May 22, 2012, which is
hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method of manufacturing
an organic light emitting display panel capable of forming a
protective insulating film in a luminescent region without causing
defects in a pattern.
[0004] 2. Discussion of the Related Art
[0005] In recent years, a variety of flat panel display devices
having reduced weight and volume, which are drawbacks of cathode
ray tubes (CRTs), have been introduced. Examples of flat panel
display devices include liquid crystal displays (LCDs), field
emission displays (FEDs), plasma display panels (PDPs), and organic
electroluminescent displays (ELDs).
[0006] Among these display devices, organic electro-luminescent
display is a self-emitting device having advantages such as rapid
response, high luminous efficacy, high luminance, and wide viewing
angle. In conventional organic electro-luminescent displays, a
plurality of thin film patterns is formed on a substrate using a
mask frame assembly.
[0007] A mask frame assembly includes transmission units
respectively corresponding to a plurality of thin film patterns, a
deposition mask having a blocking unit formed between the
transmission units, and a mask frame fixing the deposition
mask.
[0008] The deposition mask is damaged by plasma generated during a
deposition process and deformed due to reduced strength by heat
generated during the deposition process. In this regard, a deformed
blocking unit of the deposition mask cannot keep the surface flat,
thereby causing gaps. Thus, alignment accuracy between the
deposition mask and the substrate decreases during the deposition
process, resulting in deposition defects by which a thin film is
deposited on a substrate corresponding to the blocking unit.
Particularly, a protective insulating film that should be formed
only in the luminescent region using the deposition mask may also
be formed in a pad region corresponding to the blocking unit of the
deposition mask due to deformation of the deposition mask.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention is directed to a method
of manufacturing an organic light emitting display device that
substantially obviates one or more problems due to limitations and
disadvantages of the related art.
[0010] An object of the present invention is to provide a method of
manufacturing an organic light emitting display panel capable of
forming a protective insulating film in a luminescent region
without causing pattern defects.
[0011] Additional advantages, objects, and features of the
invention will be set forth in part in the description which
follows and in part will become apparent to those having ordinary
skill in the art upon examination of the following or may be
learned from practice of the invention. The objectives and other
advantages of the invention may be realized and attained by the
structure particularly pointed out in the written description and
claims hereof as well as the appended drawings.
[0012] To achieve these objects and other advantages and in
accordance with the purpose of the invention, as embodied and
broadly described herein, a method of manufacturing an organic
light emitting display panel includes forming a substrate having a
luminescent region and a pad region, simultaneously forming a light
emitting cell in the luminescent region and an organic pattern in
the pad region, forming a protective insulating film over the
substrate, bonding the substrate provided with the protective
insulating film and the sealing substrate using an adhesive film
formed in a region corresponding to the luminescent region, cutting
the bonded substrate provided with the protective insulating film
and the sealing substrate into a plurality of unit panels to expose
the pad region, and removing the protective insulating film and the
organic pattern in the exposed pad region.
[0013] The forming of the light emitting cell in the luminescent
region and the organic pattern may include simultaneously forming
at least one of an organic light emitting layer of the light
emitting cell and a bank insulating film defining the organic light
emitting layer and the organic pattern using the same material. The
organic pattern may be separated from the at least one of the
organic light emitting layer and the bank insulating film
simultaneously formed.
[0014] The removing of the protective insulating film and the
organic pattern in the exposed pad region may include adhering an
adhesive tape to the substrate, removing the protective insulating
film disposed in the pad region and adhered to the adhesive tape by
peeling off the adhesive tape, and removing the organic pattern of
the pad region by immersing the entire substrate from which the
protective insulating film is removed or the pad region in an
etchant, which may include isopropyl alcohol. The removing of the
protective insulating film and the organic pattern in the exposed
pad region may further include irradiating ultrasonic waves to the
pad region immersed in the etchant including isopropyl alcohol.
[0015] The removing of the protective insulating film and the
organic pattern in the exposed pad region may include adhering an
adhesive tape to the substrate, removing the protective insulating
film disposed in the pad region and adhered to the adhesive tape by
peeling off the adhesive tape, immersing the entire substrate from
which the protective insulating film is removed or the pad region
in deionized water, and removing the organic pattern of the pad
region by irradiating ultrasonic waves to the pad region immersed
in deionized water.
[0016] The removing of the protective insulating film and the
organic pattern in the exposed pad region may include adhering an
adhesive tape to the substrate, removing the protective insulating
film disposed in the pad region and adhered to the adhesive tape by
peeling off the adhesive tape, removing the protective insulating
film in the pad region to which the adhesive tape is adhered by
peeling-off the adhesive tape, and evaporating the organic pattern
by irradiating the organic pattern of the pad region exposed by the
removal of the protective insulating film. The exposed pad region
may be irradiated with a laser beam.
[0017] The evaporating of the organic pattern by irradiating the
organic pattern of the pad region may include evaporating the
organic pattern using energy of the laser beams absorbed by pad
electrodes having octagonal or circular shapes and formed in the
pad region to remove the organic pattern.
[0018] The adhesive tape may be adhered to the substrate to
protrude from at least one of a plurality of sides of the
substrate.
[0019] The removing of the protective insulating film and the
organic pattern in the exposed pad region may include immersing the
entire substrate or the pad region in an etchant including
isopropyl alcohol or deionized water after the cutting process, and
simultaneously removing the organic pattern of the pad region by
irradiating ultrasonic waves to the pad region immersed in the
etchant including isopropyl alcohol or deionized water and the
protective insulating film formed on the organic pattern.
[0020] It is to be understood that both the foregoing general
description and the following detailed description of the present
invention are exemplary and explanatory and are intended to provide
further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this application, illustrate embodiment(s) of
the invention and together with the description serve to explain
the principle of the invention. In the drawings:
[0022] FIG. 1 is a cross-sectional view illustrating an organic
light emitting display panel according to the present
invention;
[0023] FIGS. 2A to 2J are cross-sectional views for describing a
method of manufacturing the organic light emitting display panel of
FIG. 1;
[0024] FIGS. 3A and 3B are perspective views illustrating examples
of adhesive films used in a peel-off process of removing a
protective insulating film described with reference to FIG. 2I;
[0025] FIGS. 4A and 4B are diagrams for describing an example of a
method of removing an organic pattern described with reference to
FIG. 2J;
[0026] FIG. 5 is a diagram for describing another example of the
method of removing the organic pattern described with reference to
FIG. 2J; and
[0027] FIGS. 6A and 6B are diagrams for describing another example
of the method of removing the organic pattern described with
reference to FIG. 2J.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings. Wherever possible, the
same reference numbers will be used throughout the drawings to
refer to the same or like parts.
[0029] FIG. 1 is a cross-sectional view illustrating an organic
light emitting display panel according to the present
invention.
[0030] The organic light emitting display panel illustrated in FIG.
1 includes a light emitting substrate and a sealing substrate 134
adhered to the light emitting substrate via an adhesive film
132.
[0031] The light emitting substrate includes a plurality of thin
film transistors formed in a luminescent region of the substrate,
light emitting cells connected to the thin film transistors, and a
protective insulating film 130 formed to protect the light emitting
cells.
[0032] Each of the thin film transistors includes a gate electrode
106, a drain electrode 110 connected to a first electrode 122 of a
light emitting cell, a source electrode 108 facing the drain
electrode 110, an active layer 114 overlapping the gate electrode
106 while interposing the gate insulating layer 112 therebetween to
form a channel between the source electrode 108 and the drain
electrode 110, and an ohmic contact layer 116 formed on the active
layer 114 except for the channel region for ohmic contact between
the active layer 114 and each of the source electrode 108 and the
drain electrode 110.
[0033] An inorganic passivation layer 118 formed of an inorganic
insulating material and an organic passivation layer 128 formed of
an organic insulating material are sequentially laminated on the
thin film transistor. The organic passivation layer 128 is formed
to planarize the substrate 101 provided with the thin film
transistor thereon. The inorganic passivation layer 118 is formed
to improve stability of interfaces between the organic passivation
layer 128 and each of the gate insulating layers 112 and the source
and drain electrodes 108 and 110.
[0034] The light emitting cell includes a first electrode 122
formed on the organic passivation layer 128, an organic light
emitting layer 124 formed on the first electrode 122, and a second
electrode 126 formed on the organic light emitting layer 124.
[0035] The organic light emitting layer 124 includes a hole-related
layer, a light emitting layer, and an electron-related layer
sequentially formed on the first electrode 122 or in reverse order.
The organic light emitting layer 124 is formed in a bank hole 104
defined by a bank insulating film 102 that partitions each
luminescent region.
[0036] The first electrode 122 is electrically connected to the
drain electrode 110 of the thin film transistor via a pixel contact
hole 120 that penetrates the inorganic passivation layer 118 and
the organic passivation layer 128. The first electrode 122 may have
its structure formed by laminating an opaque conductive material
such as aluminum (Al) and a transparent conductive material such as
indium tin oxide (ITO). Alternatively, the first electrode 122 may
be formed of an acid-resistant and corrosion-resistant opaque
metal.
[0037] The second electrode 126 is formed on the organic light
emitting layer 124. The second electrode 126 is formed of a
transparent conductive material such as ITO. Thus, light generated
in the organic light emitting layer 124 is emitted upward through
the second electrode 126.
[0038] The protective insulating film 130 is disposed between the
light emitting cell and the adhesive film 132 to prevent the light
emitting cell, particularly, the organic light emitting layer 124,
from being damaged by moisture or oxygen or to prevent
deterioration of light emitting characteristics thereof.
Particularly, the protective insulating film 130 is formed to be in
contact with the adhesive film 132 to block infiltration of
moisture, hydrogen, and oxygen via side and front surfaces of the
organic light emitting display panel. The protective insulating
film 130 is formed as an inorganic insulating film using materials
such as SiN.sub.x, SiO.sub.x, or the like.
[0039] Meanwhile, a gate pad 140 and a data pad 150 are formed in a
pad region of the substrate 101 exposed by the sealing substrate
134.
[0040] The gate pad 140 is connected to a gate driving integrated
circuit (IC) and a gate line to provide a driving signal from the
gate driving IC to the gate line. To this end, the gate pad 140
includes a gate pad lower electrode 142 extending from the gate
line and a gate pad upper electrode 146 disposed on the gate pad
lower electrode 142 and connected to the gate pad lower electrode
142. In this regard, the gate pad upper electrode 146 is connected
to the gate pad lower electrode 142 via a gate contact hole 144
that penetrates the gate insulating film 112, the inorganic
passivation film 118, and the organic passivation film 128.
[0041] The data pad 150 is connected to a data driving IC and a
data line to provide a driving signal from the data driving IC to
the data line. To this end, the data pad 150 includes a data pad
lower electrode 152 extending from the data line and a data pad
upper electrode 156 disposed on the data pad lower electrode 152
and connected to the data pad lower electrode 152. In this regard,
the data pad upper electrode 156 is connected to the data pad lower
electrode 152 via a data contact hole 154 that penetrates the
organic passivation film 128 and the inorganic passivation film
118.
[0042] The sealing substrate 134 is bonded to the light emitting
substrate provided with the thin film transistor, the light
emitting cell, and the protective insulating film 130 via the
adhesive film 132, which may be disposed on the bottom surface of
the sealing substrate 134 or the top surface of the protective
insulating film 130 to seal the light emitting cell. Accordingly,
the sealing substrate 134 forms a seal that prevents external
moisture or oxygen from entering the light emitting substrate. In
addition, since the adhesive film 132 is disposed between the
bottom surface of the sealing substrate 134 and the top surface of
the protective insulating film 130 that protects the organic light
emitting layer 124, the space between the light emitting substrate
and the sealing substrate 134 is filled with the adhesive film 132.
Accordingly, the adhesive film 132 absorbs external impact,
resulting in improved rigidity of the organic light emitting
display panel according to the present invention.
[0043] FIGS. 2A to 2J are cross-sectional views for describing a
method of manufacturing the organic light emitting display panel of
FIG. 1.
[0044] Referring to FIG. 2A, a gate pattern including the gate
electrode 106 and the gate pad lower electrode 142, the gate
insulating film 112, semiconductor patterns 114 and 116, and a data
pattern including the source and drain electrodes 108 and 110 and
the data pad lower electrode 152 are sequentially formed on the
substrate 101.
[0045] Particularly, a gate metal layer is formed on the substrate
101 by a deposition method such as sputtering. In this regard, the
gate metal layer is formed using a metal such as an aluminum-based
metal (Al and AlNd), copper (Cu), titanium (Ti), molybdenum (Mo),
and tungsten (W). Then, the gate metal layer is patterned by
photolithography and etching to form the gate pattern including the
gate electrode 106 and the gate pad lower electrode 142.
[0046] Then, an inorganic insulating material such as silicon oxide
(SiO.sub.x) or silicon nitride (SiN.sub.x) may be formed over the
substrate 101 provided with the gate pattern to form the gate
insulating film 112. Then, an amorphous silicon layer and an
amorphous silicon layer doped with an impurity (n.sup.+ or p.sup.+)
are sequentially formed on the substrate 101 provided with the gate
insulating film 112. Then, the amorphous silicon layer and the
amorphous silicon layer doped with an impurity (n.sup.- or p.sup.+)
are patterned by photolithography and etching to form the
semiconductor patterns including the active layer 114 and the ohmic
contact layer 116.
[0047] Then, a data metal layer is formed on the substrate 101
provided with the semiconductor patterns by deposition such as
sputtering. In this regard, the data metal layer may be formed of
titanium (Ti), tungsten (W), an aluminum (Al)-based metal,
molybdenum (Mo), copper (Cu), or the like. Then, the data metal
layer is patterned by photolithography and etching to form the data
pattern including the source and drain electrodes 108 and 110 and
the data pad lower electrode 152. Then, a portion of the ohmic
contact layer 116 disposed between the source electrode 108 and the
drain electrode 110 is removed using the source electrode 108 and
the drain electrode 110 as masks to expose the active layer
114.
[0048] Since the semiconductor patterns 114 and 116 and the data
pattern are independently formed as described above, two masks are
required therefor. Besides, the semiconductor patterns 114 and 116
and the data pattern may be formed by use of a diffraction mask or
semi-transmissive mask or via a single mask process using a
diffraction mask, i.e., may be simultaneously formed.
[0049] Referring to FIG. 2B, the inorganic passivation film 118 and
the organic passivation film 128 having the pixel contact hole 120,
the gate contact hole 144, and the data contact hole 154 are formed
on the substrate 101 provided with the data pattern.
[0050] Particularly, the inorganic passivation film 118 is formed
by applying an inorganic insulating material such as silicon oxide
(SiO.sub.x) or silicon nitride (SiN.sub.x) over the substrate 101
provided with the data pattern. Then, the organic passivation film
128 is formed by applying an organic insulating material such as an
acrylic resin over the inorganic passivation film 118. Then, the
inorganic passivation film 118 and the organic passivation film 128
are patterned by photolithography and etching to form the pixel
contact hole 120, the gate contact hole 144, and the data contact
hole 154. The pixel contact hole 120 penetrates the inorganic
passivation film 118 and the organic passivation film 128 to expose
the drain electrode 110. The data contact hole 154 penetrates the
inorganic passivation film 118 and the organic passivation film 128
to expose the data pad lower electrode 152. The gate contact hole
144 penetrates the gate insulating film 112, the inorganic
passivation film 118, and the organic passivation film 128 to
expose the gate pad lower electrode 142.
[0051] Referring to FIG. 2C, the first electrode 122, the gate pad
upper electrode 146, and the data pad upper electrode 156 are
formed on the substrate 101 provided with the organic passivation
film 128 with the respective holes.
[0052] Particularly, an opaque conductive layer having high
reflectivity and high acid-resistance or a stack structure
including an opaque conductive layer having high reflectivity and a
transparent conductive layer having high acid-resistance may be
formed on the substrate 101 provided with the organic passivation
film 128 by deposition such as sputtering. Then, the conductive
layers are patterned by photolithography and etching to form the
first electrode 122, the gate pad upper electrode 146, and the data
pad upper electrode 156.
[0053] Referring to FIG. 2D, the bank insulating film 102 having
the bank hole 104 is formed on the substrate 101 provided with the
first electrode 122. Simultaneously, an organic pattern 148 may be
formed on the gate pad 140 and the data pad 150.
[0054] Particularly, the bank insulating film 102 having the bank
hole 104 and the organic pattern 148 are simultaneously formed by
forming an organic insulating material such as an acrylic resin
over the substrate 101 provided with the first electrode 122 and
patterning the organic insulating material by photolithography and
etching or by photolithography only. The bank hole 104 penetrates
the bank insulating film 102 of each pixel region to expose the
first electrode 122. The bank insulating film 102 is formed to
define light emitting cells realizing different colors. The organic
pattern 148 is formed to cover the gate pad upper electrode 146 and
the data pad upper electrode 156. In this regard, the bank
insulating film 102 formed in the luminescent region is isolated
from the organic pattern 148 formed to cover the gate pad upper
electrode 146 and the data pad upper electrode 156.
[0055] Referring to FIG. 2E, the organic light emitting layer 124
is formed on the substrate 101 provided with the bank insulating
film 102 and the organic pattern 148.
[0056] Particularly, the organic light emitting layer 124 including
the electron-related layer, the light emitting layer, and the
hole-related layer is formed on the portion of the first electrode
122 exposed by the hole 104 within the bank insulating film 102 by
thermal deposition, sputtering, or any combination thereof.
[0057] Referring to FIG. 2F, the second electrode 126 is formed on
the substrate 101 provided with the organic light emitting layer
124.
[0058] Particularly, the second electrode 126 is formed by coating
the substrate 101 provided with the organic light emitting layer
124 with a transparent conductive film. The transparent conductive
film may be formed of indium tin oxide (ITO), tin oxide (TO),
indium zinc oxide (IZO), SnO.sub.2, amorphous-indium tin oxide
(a-ITO), or the like.
[0059] Referring to FIG. 2G, the protective insulating film 130 is
formed over the substrate 101 provided with the second electrode
126 by depositing silicon oxide or silicon nitride over the entire
surface thereof. In this regard, the protective insulating film 130
is deposited over the entire surface of the substrate 101 without
using a deposition mask. Thus, the protective insulating film 130
is formed on the pad region including the gate pad 140 and the data
pad 150 as well as the luminescent region. Then, the adhesive film
132 is applied to the top surface of the protective insulating film
130 or the bottom surface of the sealing substrate 134. As shown,
the adhesive film 132 may be disposed such that it substantially
covers the luminescent region including the banks 102. Accordingly,
the light emitting substrate provided with the light emitting cell
is bonded to the sealing substrate 134 via the adhesive film
132.
[0060] Referring to FIG. 2H, the sealing substrate 134 and the
light emitting substrate bonded to each other are divided into a
plurality of light emitting panels. Particularly, the sealing
substrate 134 and the light emitting substrate bonded to each other
are cut along scribe lines into a plurality of light emitting
panels. After the cutting process, the pad region including the
gate pad 140 and the data pad 150 of each of the light emitting
panels is exposed to the outside by the sealing substrate 134.
[0061] Referring to FIG. 2I, a portion of the protective insulating
film 130 where the gate pad 140 and the data pad 150 are disposed
is removed by a peel-off process. Particularly, an adhesive tape
160 is attached to the substrate 101 to cover the protective
insulating film 130 formed in the pad region and exposed by
removing the corresponding sealing substrate 134 as illustrated in
FIGS. 3A and 3B. In this regard, the adhesive tape 160 illustrated
in FIG. 3A covers the bonded sealing substrate 134 and the
substrate 101 provided with the light emitting cell and has a
greater area than the substrate 101 provided with the light
emitting cell. The adhesive tape 160 illustrated in FIG. 3B has an
opening 162 that exposes the sealing substrate 134 and has a
greater area than the substrate 101 exposed by the sealing
substrate 134. The adhesive tapes 160 of FIGS. 3A and 3B include a
base film formed of polyethylene terephthalate (PET) or polyimide
and an adhesive layer formed on the base film using at least one of
silicone and acryl and has a peel strength of 50 fg/in or greater.
In addition, the adhesive tapes 160 illustrated in FIGS. 3A and 3B
have greater areas than the substrate 101 provided with the light
emitting cell to protrude from at least one of the sides of the
substrate 101 provided with the light emitting cell. Thus, the
protruded portion of the adhesive tape 160 may be used to initiate
the peel-off process, thereby facilitating the peel-off
process.
[0062] During the peel-off process of the adhesive tape 160, the
protective insulating film 130 bonded to the adhesive tape 160 is
separated from the organic pattern 148. In this regard, the
adhesive force between the protective insulating film 130 formed of
an inorganic insulating material and the organic pattern 148 formed
of an organic insulating material is lower than the adhesive force
between the organic passivation film 128 provided with the gate pad
upper electrode 146 and the data pad upper electrode 156 and the
organic pattern 148, so that only the protective insulating film
130 is removed in the peel-off process.
[0063] Referring to FIG. 2J, the organic pattern 148 disposed on
the gate pad 140 and the data pad 150 is removed by one of the
processes illustrated in FIGS. 4A to 6B to expose the gate pad 140
and the data pad 150.
[0064] Particularly, as illustrated in FIG. 4A, the pad region in
which the gate pad 140 and the data pad 150 are formed or the
entire organic light emitting display panel is immersed in an
etchant for several to several tens of minutes, for example, for 6
to 15 minutes. In this regard, the etchant may be a solution
including isopropyl alcohol (IPA). Accordingly, the organic pattern
148 disposed on the gate pad 140 and the data pad 150 is removed by
etching using the sealing substrate 134 as a mask and the etchant,
thereby exposing the gate pad upper electrode 146 and the data pad
upper electrode 156. Meanwhile, in addition to the method of
removing the organic pattern 148 by use of the etchant, the organic
pattern 148 may also be removed by immersing the pad region in an
etchant and treating the pad region with ultrasonic waves at 40 kHz
to 50 kHz and 50 W to 60 W to reduce processing time as illustrated
in FIG. 4B.
[0065] Alternatively, as illustrated in FIG. 5, only the pad region
including the gate pad 140 and the data pad 150 is immersed in
deionized water (DI), or the entire organic light emitting display
panel in which the sealing substrate and the light emitting
substrate are bonded to each other is immersed in deionized water.
Then, the pad region immersed in deionized water is treated with
ultrasonic waves at 40 kHz to 50 kHz and 50 W to 60 W, so that the
organic pattern 148 disposed on the gate pad 140 and the data pad
150 may be separated from the gate pad upper electrode 146 and the
data pad upper electrode 156. Meanwhile, the process of removing
the organic pattern 148 using deionized water and ultrasonic waves
is less harmful to the atmospheric environment and workers than the
process of removing the organic pattern 148 using IPA as
illustrated in FIG. 4A.
[0066] Meanwhile, when the pad region including the gate pad 140
and the data pad 150 is immersed in the etchant including IPA or
deionized water and treated with ultrasonic waves after the cutting
process illustrated in FIG. 2H, the organic pattern 148 is removed
from the gate pad upper electrode 146 and the data pad upper
electrode 156, so that the protective insulating film 130 formed on
the organic pattern 148 may also be removed. Accordingly, the
protective insulating film 130 and the organic pattern 148 disposed
on the gate pad 140 and the data pad 150 may be simultaneously
removed using the etchant or deionized water and ultrasonic waves
without performing the peel-off process for removing the protective
insulating film 130 disposed on the gate pad 140 and the data pad
150.
[0067] Alternatively, the organic pattern 148 disposed in the pad
region exposed by the sealing substrate 134 is removed by
irradiation, for example sequentially using a short wavelength
diode laser irradiation device 166 illustrated in FIG. 6A or by
batch irradiation of laser beams using a laser irradiation device
166 illustrated in FIG. 6B. Particularly, short wavelength linear
laser beams or short wavelength spot laser beams are irradiated to
the gate pad 140 of the pad region, energy of the laser beams is
partially absorbed by the opaque material since at least one of the
gate pad lower electrode 142 and the gate pad upper electrode 146
disposed under the organic pattern 148 is formed of an opaque
material. Thus, the organic pattern 148 formed of an organic
material and disposed on the gate pad upper electrode 146 is
evaporated by the absorbed energy and removed. In the same manner,
when laser beams are irradiated to the data pad 150 of the pad
region, energy of the laser beams is partially absorbed by the
opaque material since at least one of the data pad lower electrode
152 and the data pad upper electrode 156 disposed under the organic
pattern 148 is formed of an opaque material. Accordingly, the
organic pattern 148 formed of an organic material and disposed on
the data pad upper electrode 156 is evaporated by the absorbed
energy and removed.
[0068] Meanwhile, when the organic pattern 148 is removed by the
laser irradiation device 166, laser beams are irradiated to regions
of the organic pattern 148 corresponding to the centers of the pad
electrodes 142, 152, 146, and 156. In this case, while portions of
the organic pattern 148 formed on the central regions of the pad
electrodes 142, 152, 146, and 156, each having a rectangular
surface area, are easily removed, portions of the organic pattern
148 formed on corners of each of the pad electrodes 142, 152, 146,
and 156 farthest from the centers of the pad electrodes 142, 152,
146, and 156 are not easily removed. In order to overcome this
problem, the corners of each of the pad electrodes 142, 152, 146,
and 156 are rounded to form octagonal or circular shapes such that
the distance between the center and a circumferential position of
each of the pad electrodes 142, 152, 146, and 156 may be identical
or similar to each other. As a result, since each of the pad
electrodes 142, 152, 146, and 156 having an octagonal or circular
shape has a uniform distance between the center and each of the
sides or corners, laser beams are uniformly irradiated to the
entire area of each of the pad electrodes 142, 152, 146, and 156.
Thus, the organic pattern 148 disposed on each of the pad
electrodes 142, 152, 146, and 156 is completely removed.
[0069] Meanwhile, since a melting point of the organic pattern 148
is lower than melting points of the gate insulating film 112 and
the inorganic passivation film 118, which are formed of an
inorganic insulating material, and melting points of the pad
electrodes 142, 152, 146, and 156, the organic pattern 148 may be
removed without damaging the gate insulating film 112, the
inorganic passivation film 118, and the pad electrodes 142, 152,
146, and 156 during laser irradiation.
[0070] Meanwhile, the organic pattern 148 and the bank insulating
film 102 are simultaneously formed of the same material according
to the illustrated embodiment. However, the organic pattern 148 may
be simultaneously formed of the same material as that of at least
one organic light emitting layer 124 among an organic light
emitting layer realizing red light, an organic light emitting layer
green light, and an organic light emitting layer realizing blue
light.
[0071] According to the present invention, after an organic pattern
148 is formed in a pad region (e.g., 140, 150), and a protective
insulating film 130 is deposited over the entire surface, the
protective insulating film 130 and the organic pattern 148 are
removed. Depending on the embodiment, the insulating film 130 and
the organic pattern 148 may be sequentially or simultaneously
removed. Accordingly, since the protective insulating film 130
according to the present invention may be formed without using a
deposition mask, the protective insulating film 130 may be formed
in the luminescent region (e.g., 124) without causing defects
associated with using the deposition mask. In addition, since the
protective insulating film 130 is formed without using the
deposition mask, a mask stocker, a vision aligner, and a mask
frame, which are typically essential equipment for applying a
protective film using the deposition mask, are not required,
thereby reducing the manufacturing costs.
[0072] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention
without departing from the spirit or scope of the inventions. Thus,
it is intended that the present invention covers the modifications
and variations of this invention provided they come within the
scope of the appended claims and their equivalents.
* * * * *